A periodic density functional theory calculation: The structure of isolated copper(I) oxide species on γ-Al2O3 (1 1 0) surface and its adsorption ability toward thiophene and benzene

A periodic density functional theory approach was applied to explore the isolated copper(I) species on γ-Al2O3 (1 1 0) surface. Several potential Cu(I) centers located variously on the (1 1 0) surface of γ-alumina were modeled by attaching a Cu+ cation and removing one H+ ions from the surface hydroxyl groups. In these structures, the copper is 2-, or 3-fold bonded to the hydrated surface. The adsorption of thiophene and benzene on the structures was investigated. It was found that the coordinating environment and energy varied when isolated Cu+ located at different surface vacant sites, which resulted in different reactivity toward thiophene and benzene. And thiophene could be adsorbed preferentially on the surface supported isolated Cu species comparing to benzene. The main adsorption modes of thiophene were η1 and η2 modes, and the later was more energetically favorable.